Abstract: A phosphor powder composed of ?-sialon phosphor particles containing Eu. The phosphor powder has an ammonium ion concentration CA of the phosphor powder of equal to or more than 15 ppm and equal to or less than 100 ppm, which is determined from the following extracted ion analysis. (Extracted Ion Analysis A) 0.5 g of a phosphor powder is added to 25 ml of distilled water in a polytetrafluoroethylene (PTFE)-made container with a lid and held at 60° C. for 24 hours, and then a total mass MA of ammonium ions included in an aqueous solution obtained by removing a solid content from the solution by filtration is determined using ion chromatography. Then, CA is determined by dividing MA by the mass of the phosphor powder.

Abstract: A europium-doped ?-sialon phosphor particle. When the element concentration of a Si atom on the surface portion of the particle that is obtained by analyzing a cross section of the phosphor particle by the energy dispersive X-ray analysis method is indicated by Ps [at %], and the element concentration of a Si atom near the center of the particle that is obtained by an analysis by the same method is indicated by Pc [at %], the Pc-Ps value is 3 at % or more.

Abstract: An ?-sialon phosphor particle containing Eu. At least one minute recess is formed on a surface of the ?-sialon phosphor particle. The ?-sialon phosphor particle is preferably produced by undergoing a raw material mixing step, a heating step, a pulverizing step, and an acid treatment step.

Abstract: A europium-doped ?-sialon phosphor, in which, when the ratio of an aluminum element at a depth of 8 nm from the surface of the phosphor, which is obtained by X-ray photoelectron spectroscopy, is indicated by P8 [at %], and the ratio of an aluminum element at a depth of 80 nm from the surface of the phosphor is indicated by P80 [at %], P8/P80?0.9 is satisfied. A light emitting device containing this ?-sialon phosphor.

Abstract: A phosphor powder composed of ?-sialon phosphor particles containing Eu. In a case where an internal quantum efficiency after the phosphor powder is held at 600° C. for 1 hour in an air atmosphere is defined as P1 and an internal quantum efficiency after the phosphor powder is held at 700° C. for 1 hour in an air atmosphere is defined as P2, P1 is equal to or more than 70% and (P1?P2)/P1×100 is equal to or less than 2.8%.

Abstract: A phosphor powder composed of ?-sialon phosphor particles containing Eu. With regard to the phosphor powder, a volume-based median diameter (D50) determined by a laser diffraction scattering method is equal to or more than 10 ?m and equal to or less than 20 ?m, and a diffuse reflectance with respect to light at a wavelength of 600 nm is equal to or more than 93% and equal to or less than 99%.

Abstract: An ?-sialon phosphor particle containing Eu. At least one slit is formed on a surface of the ?-sialon phosphor particle. The ?-sialon phosphor particle is preferably produced by undergoing a raw material mixing step, a heating step, a pulverizing step, and an acid treatment step.

Abstract: A phosphor powder composed of ?-sialon phosphor particles containing Eu. In a case where an internal quantum efficiency after the phosphor powder is held at 600° C. for 1 hour in an air atmosphere is defined as P1 and an internal quantum efficiency after the phosphor powder is held at 700° C. for 1 hour in an air atmosphere is defined as P2, P1 is equal to or more than 70% and (P1?P2)/P1×100 is equal to or less than 2.8%.

Abstract: A phosphor powder composed of ?-sialon phosphor particles containing Eu. The phosphor powder has an ammonium ion concentration CA of the phosphor powder of equal to or more than 15 ppm and equal to or less than 100 ppm, which is determined from the following extracted ion analysis. (Extracted Ion Analysis A) 0.5 g of a phosphor powder is added to 25 ml of distilled water in a polytetrafluoroethylene (PTFE)-made container with a lid and held at 60° C. for 24 hours, and then a total mass MA of ammonium ions included in an aqueous solution obtained by removing a solid content from the solution by filtration is determined using ion chromatography. Then, CA is determined by dividing MA by the mass of the phosphor powder.

Abstract: An ?-sialon phosphor particle containing Eu. At least one minute recess is formed on a surface of the ?-sialon phosphor particle. The ?-sialon phosphor particle is preferably produced by undergoing a raw material mixing step, a heating step, a pulverizing step, and an acid treatment step.

Abstract: A phosphor powder composed of ?-sialon phosphor particles containing Eu. With regard to the phosphor powder, a volume-based median diameter (D50) determined by a laser diffraction scattering method is equal to or more than 10 ?m and equal to or less than 20 ?m, and a diffuse reflectance with respect to light at a wavelength of 600 nm is equal to or more than 93% and equal to or less than 99%.

Abstract: An ?-sialon phosphor particle containing Eu. At least one slit is formed on a surface of the ?-sialon phosphor particle. The ?-sialon phosphor particle is preferably produced by undergoing a raw material mixing step, a heating step, a pulverizing step, and an acid treatment step.